As the semiconductor industry advances, manufacturers are developing different packaging methods that make semiconductor components smaller, faster and more reliable. For example, chip scale packages (CSP) have a peripheral outline that is about the same as the dice contained in the packages. In addition, chip scale packages are designed for flip chip bonding to a supporting substrate, such as a package substrate, a module substrate or a printed circuit board (PCB). With flip chip bonding, bumps, pins or other terminal contacts on the package, are bonded to mating contacts on the supporting substrate. The bonded terminal contacts provide the physical and electrical connections between the package and the supporting substrate.
One important design consideration for chip scale packages is the signal transmission system between the die contacts on the dice, and the terminal contacts for the package. Some prior art chip scale packages incorporate relatively complicated electrical interconnections between the die contacts and the terminal contacts, such as beam leads, mechanical clips and edge contacts on the dice. These electrical interconnections can be unreliable and expensive to manufacture. It would be desirable for a chip scale package to have an internal signal transmission system that is reliable and capable of volume manufacture at a low cost.
One particular type of semiconductor package includes a die configured as a CMOS image sensor. With a CMOS image sensor, an active area of the die includes a photo diode, a photo transistor or a similar device configured as a light detecting element. The output of the light detecting element is an analog signal whose magnitude is approximately proportional to the amount of light received by the element. Recently, image sensor dice are being developed for use in mainstream consumer products, such as digital cameras, camcorders, and scanners. As with conventional semiconductor devices, it would be desirable to package a CMOS image sensor die in a chip scale package.
The present invention is directed to a chip scale image sensor semiconductor package, to a method for fabricating the package, and to systems incorporating the package.